The United States is experiencing one of its periodic fits of isolationism. In the age before missiles and satellites, we often felt that two oceans protected us from warring states in Asia and Europe. In addition, for over a century our own frontier kept us busy enough. Both the Founding Fathers and waves of immigrants warned us against getting too involved with the aristocratic prejudices and age-old feuds of the Old World. 

After the Civil War, the federal government turned our army into a tiny constabulary. The nation industrialized, and didn’t much worry about the rising tensions between European colonial powers. We came late to the First World War. And we left abruptly upon its conclusion. 

The Great Depression and our collective sense of “Here Europe goes again” convinced the United States to sit out the first two years of World War II until Pearl Harbor. Later, only the rise of Soviet and Chinese communism scared Americans enough to stay engaged abroad and not allow a World War III to nullify their victories against Germany and Japan. That postwar legacy of keeping the peace—given new life by the globalized spread of U.S.-inspired culture, technology, and communications—explains our present worldwide role. But lately we are growing tired of it. 

So once more there is the old isolationist tug. Americans are weary of Afghanistan and Iraq. We are the world’s largest debtor nation. The dollar has plummeted. And our leaders shrug that an ascendant China and Russia are carving out significant spheres of influence. 

Internationalism, whether economic or political, always rested on an odd, tenuous alliance of Americans. East Coast elites of both parties made the argument that our own self-interest demanded integration with like-minded democracies around the world. 

That pragmatism was also bolstered by sudden fits of public idealism. Americans were occasionally whipped up by clergymen, reporters, and diplomats to stop ignoring challenges abroad—whether that meant a canal needed building in Panama, the British were being bombed in London, or Asians were being overrun by communists. We felt we had the power to address these dangers and opportunities—and to make ourselves more secure and even prosperous in the bargain. 

Over the years, American leftists have increasingly bought into their own version of isolationism. That’s why a Noam Chomsky now often sounds like a Ron Paul.

But there was always a loose coalition of Americans who just wanted to stay home. Conservatives distrusted big government—engagement abroad usually meant more taxes, an expensive military apparatus, and the risk of surrendering sovereignty to multinational institutions. Isolationists accepted that, in theory, we might make things better abroad, but they still felt that the long-term political and financial costs would hardly be worth the effort. 

Meanwhile, by the 20th century the American left increasingly bought into isolationism—but for quite different reasons. They made the argument, especially after Vietnam, that the United States was hardly a moral state, and thus had no business spreading its pathologies abroad. Moreover, government could do better by diverting its military expenditures to entitlements and social programs here at home. No wonder a Noam Chomsky now often sounds like a Ron Paul or The Nation sometimes apes The American Conservative. 

Since World War II, mainstream Democrats and Republicans have resisted these fringes and insisted on engagement abroad—at first to repair the devastation of the war and to combat global communism, and later to bring states in Asia, Latin America, and Africa into the Western sphere of consumer capitalism and consensual government. 

But there are new dangers to this internationalism, and they don’t just come from the far left and right. The mainstream of the Democratic Party sees political advantage in damning George W. Bush for his post-9/11 commitment to spreading democracy.  Republican realists agree, and want to deal with the world as it is, rather than what it might become. 

There is also another new isolationist impulse—growing American anger at Europe. The European Union’s economy, population, and territory are getting larger than our own. Yet the EU spends little on its self-defense, preferring instead to invest billions in entitlements and in protecting European agriculture. 

In the heart of the most ardent internationalist there now grows the feeling that it might just be good for Europe or South Korea to defend itself—and for once take the flak that concrete action, not armchair moralizing, invites. Americans of every persuasion are beginning to think that a reduction in our global profile might be both profitable for ourselves and also good medicine for our friends—like when 30-something-year-old children are finally asked to move out of the house and make their own car payments. 

Still, the new isolationists and protectionists do not answer how the Westernized world would deal with China without American leadership and power. Who would contain lunatic regimes rising in South America, or Islamic terrorism, or petro-rich Middle Eastern autocracies seeking the bomb? What would be the global consequences of curtailing the lucrative, wide-open American market for India, China, and other emerging powers? 

But then isolationism and protectionism never do evoke such long-term worries. They have always followed short-term outbursts of emotion that may feel good in the here and now but are sorely regretted later. 

Victor Davis Hanson is a recipient of the 2007 National Humanities Medal.